It will be appreciate by those having general knowledge in the relevant fields that there is currently no good storage and transfer device for storing and transporting aliquots of fluid samples in hospitals and medical research labs. Although aliquot tubes and caps exist, they are typically designed for storage in one location associated with the laboratory equipment that will be used to analyze the aliquot. In particular, some laboratory equipment, such as the well-known Beckman Coulter Power Processor Automated Sample Processing System, is designed to store the aliquot tubes and to retrieve them from storage to advance them through the processing system for analysis. The tubes and caps are therefore designed sufficiently for the processing system, for example, having caps that are readily removed by the cap removal apparatus of the processing system, but are not designed suitable for transport to other laboratories, whether located within the same facility, requiring transport by person, or located at another facility, requiring transport by car, ambulance, plane, helicopter or the like.
Of course, these tubes and caps are sometimes transported, but they are known to suffer from a number of drawbacks. For example, a specific example of a prior art tube and cap is the Beckman Coulter Aliquot Tube and Cap assembly. This tube and cap combination is known to provide a weak seal between the cap and tube such that the cap can leak and even fall off if care is not taken to prevent this during transport. Additionally, the cap was never designed for courier transport. The art would therefore benefit from tube and cap combinations that provide a substantial seal between the tube and the cap so that the cap stays on absent a purposeful removal thereof and prohibits leaking when on the tube. The art would also benefit from a stronger cap not easily susceptible to distortion when gripped tightly by an individual or machine.
It should also be appreciated that any type of air transport or even ground transport to higher or lower elevations will entail a significant pressure change, and any tube and cap combination intended for such transport must be able to withstand pressure changes. Some tube and cap combinations have caps that engage tubes by means of threading (i.e. screw caps), and some of these screw cap embodiments have been found to provide suitable sealing against pressure changes. However, these screw cap embodiments are less suitable for sample processing systems in the art, which, as is known, do not provide mechanisms for replacing threaded caps onto threaded tubes, though some do provide mechanisms for removing threaded caps from threaded tubes. Push caps, that is caps removed and replaced simply by pulling the cap from and pushing the cap into the open end of the tube, are therefore preferred for use in such systems, and are further preferred because they are easier for an individual to open and close. It is believed that there currently exists no aliquot tube and push cap combination suitable for transport through such changes in pressure, and the art would therefore benefit from a tube and cap combination providing a seal that can withstand significant pressure changes.